This invention deals generally with turbine engines and more specifically with the cooling of turbine engine stators.
It is generally acknowledged that the performance of turbine engines is limited by the requirements for cooling the engine components. Although increasing engine operating temperatures would improve engine performance, such temperature increases will adversely affect the materials used for engine components unless engine cooling is significantly improved.
One of the critical components requiring cooling is the turbine nozzle. In the present designs for high pressure turbine engines, cooling of the nozzle is typically accomplished by bleeding air from the compressor and directing the air through the nozzle components to be cooled. However, such a technique adversely affects the performance of the engine. The bleeding of compressor air increases fuel consumption, decreases shaft horsepower, reduces the efficiency, and decreases the power to weight ratio.
There have been some attempts to build heat pipes into turbine components, but these efforts have not been directed toward achieving the necessary cooling effects. U.S. Pat. Nos. 4,207,027 to Barry et al and 5,439,351 to Artt have disclosed turbine airfoils with internal heat pipes, however, the goals of those patents were merely to equalize the temperature throughout the air foil, and neither patent addressed disposing of the heat to which the components were subjected.
In order to improve the performance of a high temperature turbine it is imperative, not only to equalize the temperature on the components, but also to transfer the heat to locations from which it can be removed so that the components can be maintained at lower temperatures.